Process and apparatus for the combustion firing of asphalt, petroleum and pulverizedcoal



Apnl 6, 1955 w, DE v05 $376,921

PROCESS AND APPARATUS FOR THE COMBUSTION FIRING OF ASPHALT, PETROLEUM AND PULVERIZED COAL Filed April 14, 1961 A LBERT DE VOE ATTGRNEYS United States ates fficc .idlhfizl Fatented Apr. 6, 1955 3,176,921 PRGCEdS AND MPARATUS FGR THE COMBUS- TIUN FIRING OF ASFHALT, PETRGLEUM AND PULVERIZED COAL Albert W. De Voe, 56S Danfcrth Sh, Portiand, Maine Filed Apr. 14, 1961, Ser. No. 103,137 2 Claims. (Ci. 239-8) This invention is a process and apparatus for the combustion firing of asphalt, petroleum fuels and pulverized coal.

It is an object of this invention to provide a process and apparatus for mixing asphalt, petroleum fuels or pulverized coal with air by bubbling or impact emulsification of the fuel and air with repeated rediffusion, secondary air injection, expansion, realigning and acceleration of the compounded fuel-air mixture.

Another object of the invention is to provide a process and apparatus for emulsifying a fuel-air mixture into a flame-ready condition, to eifect complete combustion of the latter at high flame temperature and producing a highly propagated flame.

A further object is to provide a gun having multiple chambers for successively treating a fuel-air mixture to progressively refine the latter prior to ignition.

Other objects of the invention will be manifest from the following description of the present preferred forms of the invention taken in connection with the accompanying drawings wherein:

FIG. 1 is a longitudinal sectional view of the assembly of the present invention, portions thereof being shown fragmentarily and in elevation;

FIG. 2 is a sectional view taken along the line 2-2 of FIG. 1, looking in the direction of the arrows;

FIG. 3 is a sectional view taken along the line 33 of FIG. 1, looking in the direction of the arrows;

FIG. 4 is a plan view of a duplex air diffusion gate constructed in accordance with the present invention, portions thereof being broken away to disclose details; and

FIG. 5 is a plan view of a modified form of a duplex air diffusion gate, portions thereof being broken away to disclose details.

Referring now in greater detail to the drawings, there is shown in FIG. 1 an assembly for the combustion firing of asphalt, petroleum fuels or pulverized coal which generally comprises a fuel gun 10, in operative connection with which is a compressed air source 11 and a fuel supply source 12.

Fuel gun 16 generally comprises a tubular body section 13, the inner periphery of which is provided with an annular shoulder 14 intermediate its length. A tubular insert 15 is fitted into the aft end of body 13 into abutting engagement with shoulder 14. Insert 15 is provided with a duplex air diffusion gate generally designated 16 in spaced relation to the outer terminal of insert 15 and a first stage emulsion diffusion gate 17 which is in spaced relation to gate 16 and in abutting relation to shoulder 14 of the gun body. That portion of gun body 13 between air diifusion gate 16 and the near terminal of the gun body comprises an air diffusion chamber designated 18. An impact emulsion chamber 19 is located in the area between diffusion gate 16 and first stage emulsion diffusion gate 17. A cap 20 is threadedly engaged over the terminal of gun body 13 and is provided with a central air opening 21.

Air diffusion gate 16 comprises a pair of parallelly arranged discs 22. and 23 respectively, each of which is provided with a series of perforations designated 2d and 25, respectively. As shown to advantage in FIGS. 1 and 4, discs 22 and 2.3 are held in permanently indexed relation to each other and in permanent spaced relationship with a predetermined pattern of perforations arranged in offset relationship to each other.

First stage emulsion diffusion gate 17 is similar in construction to air diffusion gate 16 and includes a pair of discs 26 and 27 in permanently spaced relationship, each of which is provided with a predetermined pattern of perforations 28 and 29, the perforations of the respective discs being arranged in offset relationship.

A portion of tubular body section 13 is thickened as indicated at 3%, which thickened portion is provided with a fuel intake conduit 31 which is in communication with impact emulsiiication chamber 19. In spaced relation to the conduit 31 and forward of first stage emulsion diffusion gate 17 is a fuel return conduit 32 for purposes which will be hereinafter more fully set out.

The forward bore section of tubular body 13 comprises an emulsion expansion chamber 33 which chamber extends through a substantial portion of the bodys length. An internal annular shoulder 3% is located at the forward extremity of tubular body 13. The extreme terminal of tubular body 13 is enlarged as indicated at 35, which enlarged section is internally threaded for engagement with a complementally threaded forward body section 35. Body 36 is tapered from a point intermediate its length to the terminals thereof where it is threadedly engaged at 37 with a nose cone 38.

A second stage rediifusion gate 39 is mounted at the aft end of forward body section 36 in abutting engagement with internal annular shoulder 34-. Gate 39 in cludes a pair of parallelly arranged discs 40 and 4-1 separated by a spacing ring 42. Discs 4%) and 4-1 are similar to discs 22 and 23 and include a predetermined pattern of perforations 43 and 44 arranged in offset relationship.

The bore of forward body section 2% adjacent second stage rediffusion gate 39 comprises a first stage emulsion aligning chamber 45 which extends through a substantial portion of the forward body sections length. Chamber 45 is of uniform cross-sectional area throughout. Cham ber 45 issues into a first stage emulsion accelerator chamber 46 of gradually decreasing cross-sectional area. Chamber 46 in turn issues into a second stage emulsion aligning chamber 47. At this point the bore of fuel gun 10 is appreciably reduced in cross-sectional area and the internal wall of forward section 36 is beveled to form a second stage emulsion acceleration chamber 48 of gradually decreasing cross-sectional area. Chamber 43 issues into a third stage emulsion aligning chamber 49 of uniform cross-sectional area throughout. Adjacent chamber 49 is a nose cone chamber 5% the cross-sectional area of which is substantially greater than that of chamber 49. The extreme outer terminal of nose cone 38 is provided with a Vena Contracta aperture 51 in communication with nose cone chamber 50.

Compressed air source 11 includes a storage tank 52 connected by an air line 53 to an equalizing cylinder 54 having an upper intake opening 55 through which air line 53 passes. One end of equalizing cylinder 54 is provided with an air outlet opening 56 adapted to receive one end of a charging tube 57. The opposite end of charging tube 57 is inserted into air opening 21 of tubular body cap 2% in order to feed compressed air to air diffusion chamber 18.

Equalizing cylinder 54 is further provided with side orifices 58 adapted to receive equalizing tubes 59 which extend downwardly through compiemental orifices 60 inchamber 33. 7

Fuel supply source 12 includes a storage chamber 61 which is connected to fuel supply conduit 31 by a fuel line 62. Fuel supply member 6 1 is additionally connected to fuel return conduit 32 by means of a return 7 line 63. Conventional means 64 are provided in fuel i return line 6-3 to maintain a suitable back pressure upon emulsion expansion chamber 33 and the emulsion're v maining therein.

l n conjunction with fuel gun it it is within the contemplation of the present invention to provide a refractory ring'6 which surrounds the tip of the gun through which ring secondary air is introduced in the direction of the arrows around the flame pattern. The supply of secondary-air is proportioned by conventional air gate modulathrough feed line 62 and conduit 31 to impact emulsion cha-mber 19. Compressed saturated air at approximately 80 p,-s.i.g. pressures and approximately 85% Water saturation is introduced into equalizing cylinder 54 from tank 52 through air line 53. From equalizing cylinder 54 the air is fed through charging tube 57 to air diffusion chamber '18 and through equalizing tubes 59 to emulsion expansion chamber 33.

'The compressed air entering air diffusion chamberlfi is presented to duplex air diffusion gate 16 and passes I through perforations 24 and 2.5 of disks 22 and 23, respecti-vely, in needleike streams. The needle-like streams.

I then engage the superheated fluid asphalt entering impact emulsification chamber 19 effecting'a condition within this chamber of an emulsion slurryof air and fuel; The emulsion at that time is not ready for combustion. The emul- :sioh' then passes through first stage emulsion diffusion gate 17 where a slicing-rolling in a diverse direction of the flowing emulsion improvesthe quality of the mixture to a more highly refined state, eliminating carry-over of A. flame front zone where it flashes instantly into perfect combustion at high flame temperature and, in conjunction with a supply of secondary air from pressure blower 66 produces a highly propagated flame. with a white, intensely hotflame rather than the relatively cold yellow smoky flame which up to the present tim has been produced by this type of firing.

In the firing of a hydrocarbon liquid fuel such as Bunker No. 5 residual oil or the lighter distillates of crude'oil, No. 1 and No. 2 fuel oils, the same procedure outlined above is followed with the exception that the temperatures of superheat of the fuel are changedin accordance with the flash point of the fuel being burned so as to prevent cavitation in pumps and the flashing of the fuel into a gas before discharge to the flamefront for firing.

In FIG. 5 there is illustrated a modified form of second stage rediffusion gate which is designated 39' which gate includes discs 67 and 68 which-are aligned in panallelly spaced relationin the same manner as discs 49 and 41 of gate 39. In this modified form of the invention however discs 67 and 68am not perforated in the manner of discs and 41 but are provided with aplurality of radial slots designated 69 and 70, respectively. Slots 69 and 70 are arranged in a predetermined pattern and in offset relation to each other.

Rediffusion gate 39 is particularly adapted for the firing of pulverized coal and induces a spinning action in the fuel-air stream entering the adjacent aligning cham- The asphalt burns her. In this form of the invention superheating of the.

pulverized coal is not necessary.

With the process and apparatus of the present invention the fuel-air mixture is gradually refined to effect complete combustion upon ignition from the orifice thereof.

fuel in the liquid state and presenting to expansion charnber 33 an emulsion which will uniformly accept additional air introduced through equalizing tubes 5-9. This effects further expansion of the emulsion into a flame-ready condition.

The quantity of both air and fuel supplied to the gun is always maintained in excess of the firing requirements so that a surplus of the emulsion in chamber 33 is re-.

turned to the fuel storage member 61 through fuel return conduit 32 and line 63 thereby leaving within the chamber 33 the quantity of emulsion to be burned.

The refined and expansion emulsion in chamber 33 is:

conveyed by the pressure maintained therein by back I pressure device 64 through second stage emulsion redif:

fusion gate 39, which effects the final rolling-slicing and directional diversion of the emulsion and delivers the.

emulsion in a highly refined and uniform state ready to flash into flame but requiring acceleration and perfection of stream flow before controlled release into the flame front area.

The acceleration of the emulsion to nose cone aperture 51 is accomplished in several stages of alternate alignment and acceleration. In this phase 'of the operational cycle the'flammable emulsion entering aligning chamber is aligned in traversing this chamber whereupon it passes through the tapering acceleration chamber 46 and thence to the second stage emulsion aligning chamber 47. From chamber 47 the emulsion traverses the second stage emulsion acceleration chamber 48, thence to the third stage] While only one size of gun has been illustrated, it is to be understood that various sizes may be employed and that correspondingly the number of equalizing tubes 59 may be increased as dictated by the changes in the firing range of the various sized guns. Additionally the size of the discperforations of air diffusion gate'16 may be variedto suit the particular requirement of injection stream velocity into impact emulsification'chamber 19 to accomplish the desired'emulsion for each size of gun. Various other changes may be made Within the scope of the claims hereto appended.

What is claimed is: l. A process for preparing a mixture for combustion firing comprising diffusing compressed air intothe needlelike streams in a firing gun," feeding superheated liquid asphalt to the firing gun for admixture with the needlelike streams of compressed air to produce an emulsion slurry of asphalt and air, diflusing the emulsion slurry to effect a slicing-rolling of the emulsion slurry' to refine the latter, addin'g compressed air to the emulsion slurry to effect expansion of the latter, and successively aligning and accelerating the emulsion slurry-in several stages prior to emission thereof from the firing gun.

'2'. Apparatus for the combustion firing of fuel, in-

cluding a firing gun'comprising a tubular body section, a

compressed air source in communication with one terminal of said tubular body section, pairs of spaced perforated discs in'spaced relation within said tubular body section, the perforations of said discs being in offset relation to each other, one pair of said perforated discs diffusing the compressed air, a fuel source in communication with said tubular bodysection at the locus of diffuthrough which the emulsion slurry passes and is emitted 1,512,284 Greenawalt Oct. 21, 1924 in flame-ready condition. 1,826,776 Gunther Oct. 13, 1931 2,599,422 Yettaw June 3, 1952 References Cited in the file Of this patent 2 774 5 3 Hafthe Dec 1 195 UNITED STATES PATENTS 5 2,962,225 Aghnides Nov. 29, 1960 1,427,910 Quinn Sept. 5, 1922 FOREIGN PATENTS 1428129 Balfour Sept 1922 131,108 Great Britain Au 6, 1919 1,451,063 Anthony Apr. 10, 1923 

1. A PROCESS FOR PREPARING A MIXTURE FOR COMBUSTION FIRING COMPRISING DIFFUSING COMPRESSED AIR INTO THE NEEDLELIKE STREAMS IN A FIRING GUN, FEEDING SUPERHEATED LIQUID ASPHALT TO THE FIRING GUN FOR ADMIXTURE WITH THE NEEDLELIKE STREAM OF COMPRESSED AIR TO PRODUCE AN EMULSION SLURRY OF ASPHALT AND AIR, DIFFUSING THE EMULSION SLURRY TO EFFECT A SLICING-ROLLING OF THE EMULSION SLURRY TO REFIN THE LATTER, ADDING COMPRESSED AIR TO THE EMULSION SLURRY TO EFFECT EXPANSION OF THE LATTER, AND SUCCESSIVELY ALIGNING AND ACCELERATING THE EMULSION SLURRY IN SEVERAL STAGES PRIOR TO EMISSION THEREOF FROM THE FIRING GUN. 